Stamping machine



April 9, 1940. SAIVES STAMPING MACHINE Filed Nov. 10, 1957 2 Sheets-Sheet 1 April 9, 1940. L. SAIVES STAMPING MACHINE Filed Nov. 10, 1937 2 Sheets-Sheet 2 Patented Apr. 9, 1940 STAMPING MAGHINE Leon Saives, Billancourt, France, assignor to Louis Renault, Billancourt, France Application November 10,1937, Serial No; 173,907

In France December 3, 1936 v I 1 Claim.

The present invention relates to improvements in stamping machines of the impact; class, and chiefly to machines of the plate type, in which the hammer is mounted at the lower part of a vertical plate by which it is raised after making contact with the piece of work.

It is a known fact that the stamping process serves for the production of forged pieces of exact sizes and shape, which are formed. between dies having a direct action upon the metal.

The stamping is usually effected by one of the following three methods; by impact, that is, with the use of stamp hammers and hammers of the steam or compressed air type, employing friction hammers and hammers of the plate type; by rapid pressure in which the plunger die is lowered when a hand lever is operated, said hand lever transmitting its power to the die by means of a friction device; and by slow pressure by mechanical or hydraulic presses.

The processes employing rapid pressure and slow pressure can only be used to advantage for concentric pieces (work on end), or for pieces which are die-stamped according to a plane which is parallel totheir longitudinal axis, and which do not show any great differences in section which require a preliminary drawing out and roughing with the stamp hammer.

Certain classes of machines for impact stamping, such as the stamping machines of the plate type do not sufiiciently fulfill the requirements of this method of stamping owing to the fact that they are not adapted to make, first, slight strokes in order to rapidly draw out the metal, and then, without stopping or making any special adjustment of the machine, to make heavy strokes for the final stamping of the piece. However, such machines are still utilized because of their simple construction and economical working, but it is necessary with such machines to employ auxiliary stamping machines which are adapted for the rough forging, in order to complete the work.

The improvements, the subject-matter of the invention, dispense with the use of roughing hammers, by making the hammer of the plate type better adapted for forging its own blanks, to draw them out by small and quick strokes of the hammer, and then to stamp them by the use of heavy strokes. Such operations are made at will, without stopping or intermittence, until the piece is entirely finished.

The saidimprovements realize a considerable reductionof thecost price of the stamped pieces, for the following reasons. v

1. Elimination of rough forging by a special hammer, whose installation andv operation lead to a great expense.

2. Saving of labour, owing tothe elimination of the rough-forging men.

3. Savingof power, as the stroke of the ham- 6. The production of cleaner. pieces, as these' are subjected to a single heating and hence to a less degree of oxidation.

For the better understanding of the invention, it will be more particularly described with reference to the accompanying drawings.

Fig. l is an elevational view of a stamping machine of the'known plate type, which is so adjusted as to allow only a. single length of stroke for the hammer.

Fig. 2 is a corresponding side View.

Fig. 3 relates to modifications of the hammer used in the machine shown in Fig. 1, in order to obtain a rapid stroke and a long stroke without stopping.

Figs. 4 and 5 are detail sections corresponding to Fig. 3.

- Referring to Figs. 1 and 2, it will be observed that the stamping machine of theplate type comprises a base block I which supports the lower die while the other grip i2 is movable and is actuated'by an eccentric l3, operated by a lever M which is connected by a rod I5 to a pedal 56 pivotally mounted on the lower. part of the frame.

The rollers 8-9 are constantlydriven at the same speed, but in contrarydirectio-ns, and their shafts Il-l8 have an eccentric position, in order that they may be placed at a greater or less distance from the faceof the; adjacent plate I. The shaft ll of the roller 8 is stationary, but its contact with the said plate may Joe adjusted by a lever l9 actuated by a rod 20.

On the contrary, the shaft l8 of the roller 9 may be moved towards or from the said plate by a lever 2| actuated by a controlling rod 22 whose weight is determined in such manner as to ob- .2 and carries two uprights 3-6 to which the lifting mechanism is secured, and which also,

tain a sufiicient adhesion between the roller 9 and the plate I, so that the plate can be lifted.

The control of the distance. between the roller 9 and the plate is effected by the hammer 5, during stop 23 cooperating with a driving lever 24 which is connected to the controlling rod 22 and is pivoted at 25 to an adjustable block 26 whose vertical position in a slot 2'! depends upon the desired stroke of the hammer. A fastening device 28 prevents all contact between the roller 9 and the' plate 1, before the complete fall of the hammer 5.

The said hammer drops by a free movement, and when at the end of the stroke the roller 9 makes contact with the plate 1, and owing to its adhesion and also to the adhesion of the roller 8 to the said plate, the hammer will be raised until the lever 24 takes the position shown in Fig. l, in which the roller 9 is again separated from the plate in order to allow the hammer to fall.

In other words, during the upstroke of the hammer 5, the stop 23 abuts against the driving lever 24 and forces the latter upwardly. Since the lever 24 is connected to the rod 22 and pivoted at its outer end at 26, the upward movement of the inner end of said lever 24 causes the rod 22 to be raised. The upward movement of the rod 22 causes the roller 9 to gradually move away from plate 1 until finally when the hammer 5 reaches the upper limit of its stroke, the roller 9 is' completely out of contact with said plate 1, thereby permitting the hammer 5 to drop by gravity. Of course, as the hammer, with its stop 23, moves downwardly, the rod 22 also drops by gravity thereby moving the roller 9 back toward the plate 1 until finally at the end of the downward stroke of the hammer, said roller is in contact with the plate 1 and starts the upward movement of the plate and hammer.-

Should it be desired to hold the hammer 5 in the upper position, it is simply necessary to press down the pedal l6, which actsthrough the rod I5upon the lever l4, thus bringing the grip I2 against the said plate.

This arrangement will thus provide for only one possible stroke to be made by the machine, this being the stroke for which the hammer is regulated by the vertical position of the block 26 in the slot 21.

In order to obtain two different strokes with the same hammer for a given adjustment of the block 26 to which the driving lever 24 is pivoted, I employ the following arrangement which is comprised in the invention and is shown in Figs. 3, 4 and 5.

On the hammer 5 secured to the plate 1 are mounted two stops 29-36, one of which, 29, is located at the upper part and is utilized for the P short strokes; the second stop 36 is located at the lower part, and serves for the long strokes. The said stops 29-36 are situated on the same vertical line, but their ends are not located in the same plane, as the lower stop 36 extends to some distance from the face of the hammer 5.

The driving lever 24, as before, is pivoted at 25 to the block 26 which is vertically adjustable in the slot 21 and is secured to the rod 22 which regulates the distance between the roller 9 and the plate I, but this connection between the lever 24 and the rod 22 is of such nature that the said lever can be moved in a horizontal plane in order that its end 3| may be actuated either by the upper stop 29 or by the lower stop 36 of the hammer, thus giving a greater or less stroke to the latter.

For this purpose, the lever 24 is pivotally mounted on the rod 22 by means of a device consisting of a forked bracket 32 and a bolt 33 upon which the said link is maintained by a nut 34.

The lever 24 ends in a fork 35 which is engaged in grooves formed in a hollow member 36 which is secured to the rod 37 and is mounted upon a piston-shaped shoulder 38 forming the block 26 to which the lever 24 is pivoted at 25. The said shoulder 38 is thus movable, and its vertical position can be adjusted in the groove 21. At the end of the rod 31 is located a guiding head 39, and a reaction spring 40 is mounted between this latter and the member 36. An intake of compressed air is provided at 4| between the member 36 and the shoulder 38, and a special valve controlling the admission and exhaust is secured to the operating pedal, so that the workman may supply compressed air to the member 36 or may discharge this air in order to effect the desired control of the operation of the hammer 5 of the machine, without stopping and without loss of time.

In the position shown in Figs. 3 and 4, the operating lever 24 cooperates with the upper stop 29, and thus the stroke of the hammer may be short and rapid, similar to that described in connection with Figs. 1 and 2. For this purpose, the valve has such position that the compressed air will be supplied to the member 36 through the orifice 4|. When the compressed air enters the member 36, the said member will be brought into contact with the shoulder 38, against the action of the spring 46, and thus the lever 24 will turn upon the rod 22, and its outer end will make contact with the upper stop 29, Fig. 4.

On the contrary, when the said valve is placed in the exhaust position, the compressed air is discharged from the member 36, and by the action of the spring 49 the member 36 will now be entirely in contact with the shoulder 38; the lever 24 now turns upon the rod 22, thus receding from the upper stop 29 and making contact with the lower stop 30 (Fig. 5), and the hammer 5 can now effect a longer stroke.

Owing to this modification, it is possible to construct a stamping machine of the plate type which will forge its own blanks, drawing them out by abrupt and rapid hammer strokes, and

then stamping them by long strokes, and to perform all such operations at will without stopping or intermittent action, until the piece is entirely finished.

I claim:

A stamping machine of the character described,

comprising a support, a hammer mounted for vertical movement on said support, a friction plate extending upwardly from said hammer, friction rolls on said support cooperating with the friction plate for raising the latter, a rod for moving one of said rolls toward or away from said friction plate, a pair of stops arranged on the hammer, one of said stops projecting a" greater distance from the hammer than the other, an axially extensible pivot mounted for vertical adjustment on the support, a lever mounted for horizontal shifting and vertical swinging movement on the rod and having a forked end for engagement with the pivot and arranged to coact with either of V,

the stops for actuating said rod, and means for controlling the shifting movement of the lever, whereby said lever may be shifted during operation of the machine to engage the desired stop,

said controlling means including a pressure cylinder mounted on the support and associated with the lever for extending the pivot and spring means for retracting said pivot.

LEON SAIVES. 

